nm, misread

Currently neither scatterguns nor vibroknives can be RE'd into blues/purples. As far as I've seen there's been no information as to whether this is intended or not, but because they aren't proper weapons (only used for smuggler or agent specials respectively), the RE functionality does not seem to be working on them. There have been many threads on the topic, and in not one has anyone seen a successful RE of either weapon type.

I can't speak to any other professions, but for armstech/scavenging, starting at rank 4 (where the 3rd tier of white vendor item shows up) those missions will give you MUCH better yield for the price than purchasing them off the vendor. If you're looking to make money off the profession, or just save some credits while leveling, you should take advantage of these missions while they're available, especially in bountiful or rich form. If it's actually terribly inconvenient, here's a little trick you can use. Every time you learn one of the blue/purple missions from slicing, it will completely repopulate your mission list. And there's almost always a few of these missions for sale on the GTN for cheap. So if you're really in that bad need of raw materials, you can always pick up a bioanalysis mission, learn it, then check your mission list again to see what popped up. If you get a new mission you want, great. The mission you just learned will wait for you as long as you need. If not, at least you'll get a good chunck of materials for your trouble.

You can take the transport up to the fleet at lvl 1 and train all your crew skills (which will also get you lvl 4 before you do anything from just the codex xp on all the crew trainers). However, there are no natural nodes that I know of on the starter planets. Scavengers can get some metals off strong+ droids, so that's an option. But as far as I know, there's no crystals or slice boxes or anything. I found it nice to have some early metals, but really the amount probably didn't make a difference in the long run.

I've been having the same issue with Vibroknives. It's interesting, because both are the weapons that refer to them only being used with special skills. Perhaps they can't be upgraded then? Seems odd that they were left out, but I've also gone through a pile of Desh without ever seeing a blue knife.

No, the GTN is restricted by faction. However, there is a neutral auction house on Nar Shadaa that can be viewed by both Imperial and Republic players.

Those 2 items (and any other that appear in white text) are purchased from the crew skills trade vendor. There should be one in pretty much every city's trade district.

The investigation mats are currently bugged on the GTN. They're listed under scavenging. If you want to be self-sufficient, it might be advisable to switch. But it's up to you, of course. Prices will probably dictate how important it is to get the rare mats yourself, but unfortunately, it's just too early to make any intelligent guess as to how that market will shape up.

Carbo-plas comes from Investigation missions. The only way you can get it with those crew skills is to buy it off the GTN from another player.

I've been making a lot of weapons so far, but try as I might, I can't seem to get any of the vibroknife patterns to proc blue schematics on Reverse Engineering. I also tried it a bit in beta, and no luck there either. Do the blue/purple schematics for these items exist? I guess it's possible they don't because it's not a proper weapon, just a stat stick, but I would love to know one way or another. Anyone gotten this to RE successfully?

Has this changed? As of the last beta weekend, I was consistently 1-2 tiers of crafting above my character level.

The ability to send out a companion on missions is not tied to your level. However, doing this route as you suggest, will only allow you to have 1 companion doing these missions. By the time you hit the level cap, you will have 6 companions (including the ship droid), 5 of which can be out doing missions or crafting items at the same time. The number of companions you have obviously increases as you progress through the story, and the number you can have out at a time IS tied to your character level, so it's more likely that anyone with a "crafting alt" will end up leveling it up anyway, because it's just more efficient to have more companions out doing your bidding.